Vitamin E intake and risk of amyotrophic lateral sclerosis: a pooled analysis of data from 5 prospective cohort studies

Impaired Autophagy and Defective Mitochondrial Function: Converging Paths on the Road to Motor Neuron Degeneration

Selective motor neuron degeneration is a hallmark of amyotrophic lateral sclerosis (ALS). Around 10% of all cases present as familial ALS (FALS), while sporadic ALS (SALS) accounts for the remaining 90%. Diverse genetic mutations leading to FALS have been identified, but the underlying causes of SALS remain largely unknown. Despite the heterogeneous and incompletely understood etiology, different types of ALS exhibit overlapping pathology and common phenotypes, including protein aggregation and mitochondrial deficiencies. Here, we review the current understanding of mechanisms leading to motor neuron degeneration in ALS as they pertain to disrupted cellular clearance pathways, ATP biogenesis, calcium buffering and mitochondrial dynamics. Through focusing on impaired autophagic and mitochondrial functions, we highlight how the convergence of diverse cellular processes and pathways contributes to common pathology in motor neuron degeneration.

Angiotensin-converting enzyme inhibitors and motor neuron disease: An unconfirmed association

OBJECTIVE

To investigate the association between angiotensin converting enzyme inhibitors (ACEIs), angiotensin II receptors blockers (ARBs) and motor neuron disease (MND).

METHODS

This is a population-based nested case-control study. Data were obtained from a population registry and the administrative database of the Lombardy Region (Northern Italy) from 2000 through 2010. Included were 1,200 patients with newly diagnosed MND/ALS and 120,000 controls, randomly selected from the same population and matched for gender, age and area of residence. Exposure to ACEIs or ARBs was quantified using defined daily doses (DDDs). Cumulative DDD (cDDD) was estimated as the sum of dispensed DDDs in the preceding 5 years, excluding 1 year before the MND/ALS diagnosis. Overall exposure, levels of exposure, and individual drugs were all assessed. Subgroup analyses were performed according to age, sex, ALS and ACEI-ARB association.

RESULTS

There was no significant association between MND/ALS and antecedent use of ACEIs or ARBs. Data were confirmed in multivariable models and in subgroups.

CONCLUSIONS

A protective role of ACEIs and ARBs in MND was not confirmed. Differences with a previous report (showing an inverse association between ACEIs and ALS) can be explained by different genetic background, dietary habits and susceptibility to environmental exposures, including drugs.

A look into the future of ALS research

Although amyotrophic lateral sclerosis (ALS), also referred as 'Lou Gehrig's Disease,' was first described in 1869 and the first disease-associated gene was discovered almost 20 years ago, the disease etiology is still not fully understood and treatment options are limited to one drug approved by the US Food and Drug Administration (FDA). The slow translational progress suggests that current research models are not ideal to study such a complicated disease and need to be re-examined. Progress will require greater insight into human genes and biology involved in ALS susceptibility, as well as a deeper understanding of disease phenotype at the histological and molecular levels. Improving human disease outcome will require directing focus toward improved assessment technologies and innovative approaches.

Anti-inflammatory therapies of amyotrophic lateral sclerosis guided by immune pathways

Sporadic ALS patients display heterogeneous immune pathways in peripheral blood mononuclear cells (PBMCs). We tested nine sALS patients and one unaffected identical twin of an index case by RNA-Seq of PBMCs. The inflammatory patients (n = 3) clustered into a subset with an inflammatory Th1/Th17 signature and the non-inflammatory patients (n = 7) into another subset with a B cell signature. The inflammatory subset was remarkable for granulocyte and agranulocyte diapedesis, hepatic fibrosis, roles of cytokines and metalloproteases. The non-inflammatory subset was highlighted by degradation of vitamin E, serotonin and nucleotides, altered T cell and B cell signaling, agranulocyte diapedesis, and up regulation of B cell genes. Identification of these differentially regulated pathways in sALS patients may guide the choice of anti-inflammatory therapies.

A comprehensive review of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disease affecting motor neurons with an incidence of about 1/100,000. Most ALS cases are sporadic, but 5–10% of the cases are familial ALS. Both sporadic and familial ALS (FALS) are associated with degeneration of cortical and spinal motor neurons. The etiology of ALS remains unknown. However, mutations of superoxide dismutase 1 have been known as the most common cause of FALS. In this study, we provide a comprehensive review of ALS. We cover all aspects of the disease including epidemiology, comorbidities, environmental risk factor, molecular mechanism, genetic factors, symptoms, diagnostic, treatment, and even the available supplement and management of ALS. This will provide the reader with an advantage of receiving a broad range of information about the disease.

Complementary and Alternative Therapies in Amyotrophic Lateral Sclerosis

Given the severity of their illness and lack of effective disease-modifying agents, it is not surprising that most patients with amyotrophic lateral sclerosis (ALS) consider trying complementary and alternative therapies. Some of the most commonly considered alternative therapies include special diets, nutritional supplements, cannabis, acupuncture, chelation, and energy healing. This article reviews these in detail. The authors also describe 3 models by which physicians may frame discussions about alternative therapies: paternalism, autonomy, and shared decision making. Finally, the authors review a program called ALSUntangled, which uses shared decision making to review alternative therapies for ALS.

Rosmarinic Acid Alleviates Neurological Symptoms in the G93A-SOD1 Transgenic Mouse Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects motor neurons in the brain and spinal cord, resulting in paralysis of voluntary skeletal muscles and eventually death, usually within 2~3 years of symptom onset. The pathophysiology mechanism underlying ALS is not yet clearly understood. Moreover the available medication for treating ALS, riluzole, only modestly improves neurological symptoms and increases survival by a few months. Therefore, improved therapeutic strategies are urgently needed. In the present study, we investigated whether rosmarinic acid has a therapeutic potential to alleviate neurological deterioration in the G93A-SOD1 transgenic mouse model of ALS. Treatment of G93A-SOD1 transgenic mice with rosmarinic acid from 7 weeks of age at the dose of 400 mg/kg/day significantly extended survival, and relieved motor function deficits. Specifically, disease onset and symptom progression were delayed by more than one month. These symptomatic improvements were correlated with decreased oxidative stress and reduced neuronal loss in the ventral horns of G93A-SOD1 mice. These results support that rosmarinic acid is a potentially useful supplement for relieving ALS symptoms.

The interplay between metabolic homeostasis and neurodegeneration: insights into the neurometabolic nature of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disease that is characterized by the selective degeneration of upper motor neurons and lower spinal motor neurons, resulting in the progressive paralysis of all voluntary muscles. Approximately 10 % of ALS cases are linked to known genetic mutations, with the remaining 90 % of cases being sporadic. While the primary pathology in ALS is the selective death of upper and lower motor neurons, numerous studies indicate that an imbalance in whole body and/or cellular metabolism influences the rate of progression of disease. This review summarizes current research surrounding the impact of impaired metabolic physiology in ALS. We extend ideas to consider prospects that lie ahead in terms of how metabolic alterations may impact the selective degeneration of neurons in ALS and how targeting of adenosine triphosphate-sensitive potassium (K_ATP) channels may represent a promising approach for obtaining neuroprotection in ALS.

Intakes of caffeine, coffee and tea and risk of amyotrophic lateral sclerosis: Results from five cohort studies

Caffeine is thought to be neuroprotective by antagonizing the adenosine A2A receptors in the brain and thereby protecting motor neurons from excitotoxicity. We examined the association between consumption of caffeine, coffee and tea and risk of amyotrophic lateral sclerosis (ALS). Longitudinal analyses based on over 1,010,000 males and females in five large cohort studies (the Nurses' Health Study, the Health Professionals Follow-up Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort Study, and the National Institutes of Health-AARP Diet and Health Study). Cohort-specific multivariable-adjusted risk ratios (RR) and 95% confidence intervals (CI) estimates of ALS incidence or death were estimated by Cox proportional hazards regression and pooled using random-effects models. Results showed that a total of 1279 cases of ALS were documented during a mean of 18 years of follow-up. Caffeine intake was not associated with ALS risk; the pooled multivariable-adjusted RR comparing the highest to the lowest quintile of intake was 0.96 (95% CI 0.81-1.16). Similarly, neither coffee nor tea was associated with ALS risk. In conclusion, the results of this large study do not support associations of caffeine or caffeinated beverages with ALS risk.

Risk factors for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. It is typically fatal within 2-5 years of symptom onset. The incidence of ALS is largely uniform across most parts of the world, but an increasing ALS incidence during the last decades has been suggested. Although recent genetic studies have substantially improved our understanding of the causes of ALS, especially familial ALS, an important role of non-genetic factors in ALS is recognized and needs further study. In this review, we briefly discuss several major genetic contributors to ALS identified to date, followed by a more focused discussion on the most commonly examined non-genetic risk factors for ALS. We first review factors related to lifestyle choices, including smoking, intake of antioxidants, physical fitness, body mass index, and physical exercise, followed by factors related to occupational and environmental exposures, including electromagnetic fields, metals, pesticides, β-methylamino-L-alanine, and viral infection. Potential links between ALS and other medical conditions, including head trauma, metabolic diseases, cancer, and inflammatory diseases, are also discussed. Finally, we outline several future directions aiming to more efficiently examine the role of non-genetic risk factors in ALS.

A Cystine-Rich Whey Supplement (Immunocal(®)) Delays Disease Onset and Prevents Spinal Cord Glutathione Depletion in the hSOD1(G93A) Mouse Model of Amyotrophic Lateral Sclerosis

Depletion of the endogenous antioxidant, glutathione (GSH), underlies progression of the devastating neurodegenerative disease, amyotrophic lateral sclerosis (ALS). Thus, strategies aimed at elevating GSH may yield new therapeutics for ALS. Here, we investigated the effects of a unique non-denatured whey protein supplement, Immunocal(®), in the transgenic Gly position 93 to Ala (G93A) mutant hSOD1 (hSOD1(G93A)) mouse model of ALS. Immunocal(®) is rich in the GSH precursor, cystine, and is therefore capable of bolstering GSH content. Transgenic hSOD1(G93A) mice receiving Immunocal(®) displayed a significant delay in disease onset compared to untreated hSOD1(G93A) controls. Additionally, Immunocal(®) treatment significantly decreased the rate of decline in grip strength and prevented disease-associated reductions in whole blood and spinal cord tissue GSH levels in end-stage hSOD1(G93A) mice. However, Immunocal(®) did not extend survival, likely due to its inability to preserve the mitochondrial GSH pool in spinal cord. Combination treatment with Immunocal(®) and the anti-glutamatergic compound, riluzole, delayed disease onset and extended survival in hSOD1(G93A) mice. These findings demonstrate that sustaining tissue GSH with Immunocal(®) only modestly delays disease onset and slows the loss of skeletal muscle strength in hSOD1(G93A) mice. Moreover, the inability of Immunocal(®) to rescue mitochondrial GSH in spinal cord provides a possible mechanism for its lack of effect on survival and is a limiting factor in the potential utility of this supplement as a therapeutic for ALS.

Dietary ω-3 polyunsaturated fatty acid intake and risk for amyotrophic lateral sclerosis

IMPORTANCE

Amyotrophic lateral sclerosis (ALS) is a severe progressive disease that cannot be prevented or cured. Diet-derived long-chain polyunsaturated fatty acids (PUFAs) are incorporated in brain lipids and modulate oxidative and inflammatory processes and could thus affect ALS risk and progression.

OBJECTIVE

To examine the association between ω-6 and ω-3 PUFA consumption and ALS risk.

DESIGN, SETTING, AND PARTICIPANTS

Longitudinal analyses based on 1,002,082 participants (479,114 women and 522,968 men) in 5 prospective cohorts: the National Institutes of Health-AARP Diet and Health Study, the Cancer Prevention Study II Nutrition Cohort, the Health Professionals Follow-up Study, the Multiethnic Cohort Study, and the Nurses' Health Study. Diet was assessed via food frequency questionnaire developed or modified for each cohort. Participants were categorized into cohort-specific quintiles of intake of energy-adjusted dietary variables.

MAIN OUTCOMES AND MEASURES

Cohort-specific multivariable-adjusted risk ratios (RRs) of ALS incidence or death estimated by Cox proportional hazards regression and pooled using random-effects methods.

RESULTS

A total of 995 ALS cases were documented during the follow-up. A greater ω-3 PUFA intake was associated with a reduced risk for ALS. The pooled, multivariable-adjusted RR for the highest to the lowest quintile was 0.66 (95% CI, 0.53-0.81; P < .001 for trend). Consumption of both α-linolenic acid (RR, 0.73; 95% CI, 0.59-0.89; P = .003 for trend) and marine ω-3 PUFAs (RR, 0.84; 95% CI, 0.65-1.08; P = .03 for trend) contributed to this inverse association. Intakes of ω-6 PUFA were not associated with ALS risk.

CONCLUSIONS AND RELEVANCE

Consumption of foods high in ω-3 PUFAs may help prevent or delay the onset of ALS.

Palliative Care Issues in Amyotrophic Lateral Sclerosis: An Evidenced-Based Review

As palliative care physicians become increasingly involved in the care of patients with amyotrophic lateral sclerosis (ALS), they will be asked to provide guidance regarding the use of supplements, diet, exercise, and other common preventive medicine interventions. Moreover, palliative care physicians have a crucial role assisting patients with ALS in addressing health care decisions to maximize quality of life and cope with a rapidly disabling disease. It is therefore important for palliative care physicians to be familiar with commonly encountered palliative care issues in ALS. This article provides an evidenced-based review of palliative care options not usually addressed in national and international ALS guidelines.

Dietary fiber and amyotrophic lateral sclerosis: results from 5 large cohort studies

Amyotrophic lateral sclerosis (ALS) is a fast-progressing neurodegenerative disease with a median survival time from diagnosis of 1.5-3 years. The cause of ALS is unknown, but inflammation may play a role. Fiber has been shown to lower inflammatory markers, and a high fiber intake was associated with a lower risk of ALS in a case-control study; however, prospective studies are lacking. We explored the relation between dietary intake of fiber and the risk of ALS in 5 large prospective cohort studies comprising over 1,050,000 US citizens who contributed 1,133 ALS cases during a mean of 15 years of follow-up (1980-2008). Cox proportional hazards models were used within each cohort, and cohort-specific estimates were subsequently pooled using a random-effects model. We found that intakes of total fiber, cereal fiber, vegetable fiber, and fruit fiber were not associated with ALS risk when comparing the highest quintile of intake with the lowest (for total fiber, pooled multivariable relative risk (RR) = 0.99, 95% confidence interval (CI): 0.80, 1.24; for cereal fiber, RR = 1.13, 95% CI: 0.94, 1.37; for vegetable fiber, RR = 0.97, 95% CI: 0.77, 1.23; and for fruit fiber, RR = 1.05, 95% CI: 0.86, 1.29). These findings do not support the hypothesis that fiber intake is a major determinant of ALS risk.

Clinical perspective on oxidative stress in sporadic amyotrophic lateral sclerosis

Sporadic amyotrophic lateral sclerosis (ALS) is one of the most devastating neurological diseases; most patients die within 3 to 4 years after symptom onset. Oxidative stress is a disturbance in the pro-oxidative/antioxidative balance favoring the pro-oxidative state. Autopsy and laboratory studies in ALS indicate that oxidative stress plays a major role in motor neuron degeneration and astrocyte dysfunction. Oxidative stress biomarkers in cerebrospinal fluid, plasma, and urine are elevated, suggesting that abnormal oxidative stress is generated outside of the central nervous system. Our review indicates that agricultural chemicals, heavy metals, military service, professional sports, excessive physical exertion, chronic head trauma, and certain foods might be modestly associated with ALS risk, with a stronger association between risk and smoking. At the cellular level, these factors are all involved in generating oxidative stress. Experimental studies indicate that a combination of insults that induce modest oxidative stress can exert additive deleterious effects on motor neurons, suggesting that multiple exposures in real-world environments are important. As the disease progresses, nutritional deficiency, cachexia, psychological stress, and impending respiratory failure may further increase oxidative stress. Moreover, accumulating evidence suggests that ALS is possibly a systemic disease. Laboratory, pathologic, and epidemiologic evidence clearly supports the hypothesis that oxidative stress is central in the pathogenic process, particularly in genetically susceptive individuals. If we are to improve ALS treatment, well-designed biochemical and genetic epidemiological studies, combined with a multidisciplinary research approach, are needed and will provide knowledge crucial to our understanding of ALS etiology, pathophysiology, and prognosis.

Therapeutic neuroprotective agents for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal chronic neurodegenerative disease whose hallmark is proteinaceous, ubiquitinated, cytoplasmic inclusions in motor neurons and surrounding cells. Multiple mechanisms proposed as responsible for ALS pathogenesis include dysfunction of protein degradation, glutamate excitotoxicity, mitochondrial dysfunction, apoptosis, oxidative stress, and inflammation. It is therefore essential to gain a better understanding of the underlying disease etiology and search for neuroprotective agents that might delay disease onset, slow progression, prolong survival, and ultimately reduce the burden of disease. Because riluzole, the only Food and Drug Administration (FDA)-approved treatment, prolongs the ALS patient's life by only 3 months, new therapeutic agents are urgently needed. In this review, we focus on studies of various small pharmacological compounds targeting the proposed pathogenic mechanisms of ALS and discuss their impact on disease progression.

Dietary intake of fruits and beta-carotene is negatively associated with amyotrophic lateral sclerosis risk in Koreans: a case-control study

OBJECTIVES

Amyotrophic lateral sclerosis (ALS), a rare progressive neurodegenerative disease, has been suggested to have an association with oxidative stress, and thus antioxidant dietary factors may influence pathophysiological mechanisms or the risk of ALS. The purpose of the present study was to investigate the hypothesis that intake of fruits, rich in antioxidant nutrients, is negatively associated with the risk of ALS.

METHODS

Seventy-seven Koreans diagnosed with ALS according to the EI Escorial criteria-revised and the same number of age- and sex-matched healthy controls participated in this study. Dietary intake was estimated using the standardized food frequency questionnaire.

RESULTS

Multivariate logistic regression analysis showed that fruit consumption was negatively associated with the risk of ALS, but intake of beef, fish, and fast food were positively associated with the risk of ALS. In addition, the risk of ALS was negatively associated with intake of plant calcium and beta-carotene, while positively associated with intake of total calcium and animal calcium. Intake of vegetables and other antioxidant nutrients had no effect on the risk of ALS in the present study.

DISCUSSION

The intake of fruits and beta-carotene decreases the risk of sporadic ALS in this present study. However, large prospective and interventional studies are needed to confirm the effect of fruits and beta-carotene intake on the risk of ALS.

Early-onset alopecia and amyotrophic lateral sclerosis: a cohort study

A recent meta-analysis of 7 genome-wide association studies on early balding (alopecia) revealed single nucleotide polymorphism variants in the region of the amyotrophic lateral sclerosis (ALS) gene TAR DNA-binding protein 43 (TARDBP/TDP-43). We therefore explored the association of early-onset alopecia and ALS in the Health Professionals Follow-up Study, a large cohort of 51,529 US men. In 1992, the participants (then aged 46-81 years) were asked to report their hair line pattern at age 45 years. During the follow-up period (1992-2008), 42 men were diagnosed with ALS. Of those, 13 had reported no alopecia, 18 had reported moderate alopecia, and 11 had reported extensive alopecia at age 45 years. Those who reported extensive alopecia had an almost 3-fold increased risk of ALS compared with those who reported no alopecia (relative risk = 2.74, 95% confidence interval: 1.23, 6.13). Furthermore, we observed a linear trend of increased risk of ALS with increasing level of balding at age 45 years (Ptrend = 0.02). In conclusion, men with early-onset alopecia seem to have a higher risk of ALS. The mechanisms underlying this association deserve further investigation.

Magnesium intake and risk of amyotrophic lateral sclerosis: results from five large cohort studies

A low magnesium intake has been suggested to be associated with amyotrophic lateral sclerosis (ALS) in pathological and case-control studies, but prospective studies in humans are lacking. The relation between dietary intake of magnesium and ALS risk was explored in five large prospective cohort studies (the Nurses' Health Study, the Health Professionals Follow-up Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort Study, and the National Institutes of Health - AARP Diet and Health Study), comprising over 1,050,000 males and females contributing 1093 cases of ALS during a mean of 15 years of follow-up. Cox proportional hazards models were used within each cohort, and cohort-specific estimates were subsequently pooled using a random-effects model. Results demonstrated that dietary magnesium intake was not associated with ALS risk, relative risk 1.07, 95% confidence interval 0.88 - 1.31 comparing the highest quintile of intake with the lowest. This finding does not support a protective effect of magnesium intake on ALS risk. Further analyses should explore magnesium intake in combination with heavy metal exposure and genetic variants affecting magnesium absorption.

[Amyotrophic lateral sclerosis: update on etiological treatment]

Amyotrophic lateral sclerosis is a rare neurodegenerative disease. It is characterized by motoneurons progressive degeneration. Associated with a paralysis of the legs, arms and the respiratory muscles, its evolution is lethal. Riluzole is the only drug available with an marketing authorisation (autorisation de mise sur le marché [AMM]) in this indication. In the beginning stages of the disease it demonstrated a modest efficacy by prolonging survival for a few months. Although the physiopathological mechanisms of this disease have not been totally solved, the progression of knowledge in recent years in this area led to the development of a large number of neuroprotective agents which showed effective results in animal models of ALS and which could be good candidates for the treatment of ALS. Several clinical trials have been conducted about antiglutamatergic, antioxidant, antiapoptotic agents and growing cell factors but they failed to demonstrate efficacy on survival or quality of life. Therefore, clinical trials using innovative therapeutics and stem cells are ongoing and offer more distant hope.

Current pathways for epidemiological research in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease. The current status of the epidemiology, challenges to its study, and novel study design options are discussed in this paper. We focus on recent results from large-scale population based prospective studies, case-control studies and population based registries, risk factors, and neuropathologic findings in chronic traumatic encephalomyelopathy. We identify areas of interest for future research, including time-trends in the incidence and prevalence of ALS; the meaning of lifetime risk; the phenotypic description of ALS; the definition of familial versus sporadic ALS, syndromic aspects of ALS; specific risk factors such as military service, life style factors such as smoking, the use of statins, and the presence of β-N-methylamino-L-alanine (BMAA), an excitotoxic amino acid derivative possibly produced by cyanobacteria found in almost every terrestrial and aquatic habitat; the emergence and disappearance of an endemic ALS in areas of the Pacific; and gene-environment interactions in the etiology of ALS. To move the epidemiology forward, we suggest using well-characterized cohorts of newly diagnosed ALS patients to identify risk and prognostic factors; storing biological material for future studies; building on the National ALS Registry as a resource of future studies; working in multidisciplinary consortia; and addressing the possible early life etiology of ALS.

Vitamin E serum levels and controlled supplementation and risk of amyotrophic lateral sclerosis

There are no observational studies or controlled trials of amyotrophic lateral sclerosis (ALS) and circulating α-tocopherol (vitamin E) for prevention of ALS. This study addresses that gap. The study population comprised 29,127 Finnish male smokers, aged 50-69 years, who participated in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, which is both a prospective cohort and a randomized, double-blind, placebo-controlled trial of α-tocopherol (50 mg/day) and β-carotene (20 mg/day). Serum α-tocopherol and β-carotene was assayed at baseline (1985 - 1988). Follow-up (median 16.7 years) continued through 2004. ALS cases were identified through the national Hospital Discharge Register with diagnostic verification by hospital records and death certificates. During 407,260 person-years of follow-up, 50 men were identified with ALS. For males with serum α-tocopherol concentration above the median (≥ 11.6 mg/l), the age-adjusted relative risk (RR) compared to α-tocopherol below the median, was 0.56 (95% confidence interval 0.32 - 0.99), p = 0.046. The RR among α-tocopherol supplement recipients was 0.75 (95% CI 0.32 - 1.79), p = 0.52. Neither serum β-carotene level nor β-carotene supplementation was associated with ALS. In conclusion, the results are consistent with a hypothesized protective effect of α-tocopherol on ALS risk. However, pooled analyses of cohorts with serum and controlled trials are needed to clarify the role of α-tocopherol in ALS risk.

Intakes of vitamin C and carotenoids and risk of amyotrophic lateral sclerosis: pooled results from 5 cohort studies

OBJECTIVE

Prior research has suggested the possible role of oxidative stress in the pathogenesis of amyotrophic lateral sclerosis (ALS). Prospective data examining dietary antioxidants such carotenoids and vitamin C are limited.

METHODS

Risk of ALS associated with carotenoid and vitamin C intake was investigated in 5 prospective cohorts: the National Institutes of Health-Association of American Retired Persons Diet and Health Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort, the Health Professionals Follow-up Study (HPFS), and the Nurses Health Study (NHS). ALS deaths were documented using the National Death Index, and confirmed nonfatal ALS cases were included from HPFS and NHS. A total of 1,153 ALS deaths occurred among 1,100,910 participants (562,942 men; 537,968 women). Participants were categorized into cohort-specific quintiles of intake for dietary variables. We applied Cox proportional hazards regression to calculate cohort-specific risk ratios (RRs), and pooled results using random-effects methods.

RESULTS

A greater total major carotenoids intake was associated with a reduced risk of ALS (pooled, multivariate-adjusted RR for the highest to the lowest quintile = 0.75, 95% confidence interval [CI] = 0.61-0.91, p for trend = 0.004). Individually, higher dietary intakes of β-carotene and lutein were inversely associated with ALS risk. The pooled multivariate RRs comparing the highest to the lowest quintile for β-carotene and lutein were 0.85 (95% CI = 0.64-1.13, p for trend = 0.03) and 0.79 (95% CI = 0.64-0.96, p for trend = 0.01), respectively. Lycopene, β-cryptoxanthin, and vitamin C were not associated with reduced risk of ALS.

INTERPRETATION

Consumption of foods high in carotenoids may help prevent or delay onset of ALS.

Non-steroidal anti-inflammatory drugs and amyotrophic lateral sclerosis: results from five prospective cohort studies

Animal and pathological studies suggest that inflammation may contribute to amyotrophic lateral sclerosis (ALS) pathology and that non-steroidal anti-inflammatory drugs (NSAIDs) might be protective. However, there are no prospective data on the relation between NSAID use and ALS risk in humans. The relation between NSAID use and ALS risk was explored in five large prospective cohort studies (the Nurses' Health Study, the Health Professionals Follow-up Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort Study, and the National Institutes of Health - AARP Diet and Health Study). Detailed NSAID information was sought from 780,000 participants, 708 of whom developed ALS during follow-up. Cox proportional hazards models were used within each cohort and cohort-specific estimates were pooled with random effects models. Results showed that neither non-aspirin NSAID use, nor aspirin use was associated with ALS risk overall. The multivariable, pooled relative risk was 0.96 (95% CI 0.76-1.22) among non-aspirin NSAID users compared with non-users. Duration of NSAID use in years and frequency of NSAID use were not associated with ALS risk overall. In conclusion, the results do not support an overall effect of NSAIDs on ALS risk, but because NSAIDs have heterogeneous effects, a role of individual compounds cannot be excluded.

Promotion of plasma membrane repair by vitamin E

Severe vitamin E deficiency results in lethal myopathy in animal models. Membrane repair is an important myocyte response to plasma membrane disruption injury as when repair fails, myocytes die and muscular dystrophy ensues. Here we show that supplementation of cultured cells with α-tocopherol, the most common form of vitamin E, promotes plasma membrane repair. Conversely, in the absence of α-tocopherol supplementation, exposure of cultured cells to an oxidant challenge strikingly inhibits repair. Comparative measurements reveal that, to promote repair, an anti-oxidant must associate with membranes, as α-tocopherol does, or be capable of α-tocopherol regeneration. Finally, we show that myocytes in intact muscle cannot repair membranes when exposed to an oxidant challenge, but show enhanced repair when supplemented with vitamin E. Our work suggests a novel biological function for vitamin E in promoting myocyte plasma membrane repair. We propose that this function is essential for maintenance of skeletal muscle homeostasis.

Membrane repair of myocytes is important to prevent such disease as muscular dystrophy but the properties of this repair are not well characterised. In this study, vitamin E is shown to be important in the repair of myocyte cell membranes in cultured cells and in intact muscle.